Decentralized source separation sewage system

ABSTRACT

An apparatus and method for treating sewage The apparatus receives sewage at a receiving compartment and separates solids from liquids at the receiving compartment. The solids can be extracted from the receiving compartment by an auger. The liquid sewage flows through a series of treatment compartment containing rotating biological contactor discs for treatment by these rotating biological contactor discs. The rotating biological contactor discs are secured to a rotating shaft. The rotating shaft and the auger are powered by a quasi-submerged turbine displaced by a flow of air.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 61/053,466 filed May 15, 2008, and of U.S.Provisional Patent Application No. 61/042,820 filed Apr. 7, 2008, bothwhich are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to sewage systems. Moreparticularly, the present invention relates to decentralized sewagesystems.

BACKGROUND OF THE INVENTION

Water management is becoming increasingly important, especially inwater-scarce regions of the world, such as, for example, the Sun Belt inthe U.S.A. In such regions, water taxes are usually high and, as such,there is a strong incentive to conserve and recover water.

Further, the management and treatment of sewage water is also becomingincreasingly important due to costs associated thereto, environmentalconcerns, and stricter disposal criteria.

In areas were a municipal sewage system is not available, decentralizedsewage systems such as, for example, septic tanks can be used. Suchseptic tanks usually have two compartments, with a first compartmentreceiving wastewater, and the second compartment outputting treatedwater to a leach field (also referred to as a drain field or seepagefiled), which can span over a large area, for example, from 200 to 300m² for a three-bedroom house. Solids in the wastewater fall to thebottom of the first compartment while scum floats to the surface. Adivider between the first and second compartments has an opening thatallows scummy water to flow from the first to the second compartmentwhere additional settling of solids in the water can occur. Anaerobicbacterial activity in the first and second compartments turns the soliddeposits into sludge. The liquid present in the second compartmentproceeds through the output of the septic tank, into the leach fieldwhere the impurities present in the water decompose in the soil.

Septic tanks must be cleaned out of their sludge on a regular basis.This typically involves a service truck pumping out the compartments ofa tank and bringing the sludge to a municipal sewage treatment plantwhere the sludge is dumped and treated.

Characteristically, at such sewage treatment plants, the sludge mixes inwith various pollutants and chemical generated by industries that alsouse the municipal sewage treatment plant. This causes sludgeconstituents to bind to these pollutants and chemicals to produce toxinsthat can be extremely difficult to eliminate. Typically, such toxins areeliminated by a costly burning process.

Decentralized sewage systems, other than septic tank systems, includethose using rotating biological contactor disks (RBCDs) placed in acontainer vessel receiving sewage water. In such systems, space-apartdisks are mounted on a rotating shaft and are partially submerged insewage water. The RBCDs, which can be made of plastic, or of any othersuitable material, accumulate bacteria over time. As the RBCDs rotate inthe sewage water, the bacteria capture and digest matter of the sewagewater. As the RBCDs rotates out the water and become exposed to air, theaeration facilitates the digestion of the matter by the bacteria formedon the RBCDs, which turns the sewage matter into biomass on the RBCDs.The treated sewage water is output from the vessel into a leach field.

After a period of time over which the RBCDs accumulate biomass, thebiomass will break off from the RBCDs and fall to the bottom of thevessel. Regular pumping of the biomass accumulated at the bottom of thevessel is required.

Typically, the sewage water arrives directly into the vessel anddissolves therein. As such, a large number of RBCDs are required toensure adequate treatment of the sewage water. Additionally, RBCDsystems typically require an electrical motor to rotate the shaft anddisks. The motor has to operate in a constantly humid environment and,as such, is prone to short and medium term failures, in which cases, theefficiency of the sewage treatment system falls off drastically.

It is, therefore, desirable to provide a decentralized sewage treatmentthat allows for separation of solid matter at the source, that hasoperational reliability, that has a small leach field footprint and thatproduces reusable water.

SUMMARY OF THE INVENTION

It is an object of the present invention to obviate or mitigate at leastone disadvantage of previous sewage treatment systems.

In a first aspect, the present invention provides an apparatus fortreating sewage, with the sewage including water and waste products. Theapparatus comprises a housing and a sewage receiver compartment formedwithin the housing. The sewage receiver compartment has a sewage inletto receive the sewage therefrom. The sewage receiver compartment has abottom portion. Some of the waste products in the sewage to sink to thebottom portion to form a solid matter deposit. The apparatus furthercomprises a first treatment compartment formed within the housing. Thefirst treatment compartment is in fluid communication with the sewagereceiver compartment. The first treatment compartment is to receive thesewage from the sewage receiver compartment. The apparatus furthercomprises an auger mounted within the housing, the auger having firstand second ends. The first end is disposed at the bottom portion of thesewage receiver compartment. The apparatus also comprises a receptacledisposed outside the sewage receiver compartment, adjacent the secondend of the auger. The apparatus further comprises a rotatable shaftmounted in the housing. The rotatable shaft extends through the firsttreatment compartment. The rotatable shaft has a biological contactormaterial secured thereto. The biological contactor material is disposedin the first treatment compartment. The apparatus further comprises aturbine compartment formed within the housing and in fluid communicationwith the first treatment compartment. A turbine is rotatably mounted inthe turbine compartment and operationally connected to the rotatableshaft and to the second end of the auger. The apparatus furthercomprises an air source operationally coupled to the turbine. The airsource is to turn the turbine and the turbine is to rotate the rotatableshaft to cause the biological contactor material successively passingthough the sewage, and through air, as the rotatable shaft rotates. Thesuccessive passage of the biological contactor material through thesewage and through the air causes micro-organisms to form on thebiological contactor material and to consume a portion of the wasteproducts present in the sewage in order to produce treated water. Theturbine also rotates the auger. The auger displaces, upon rotation, thesolid matter deposit from the bottom portion of the sewage receivercompartment to the receptacle. The apparatus further comprises an outletin fluid communication with the first treatment compartment, and with aleach field, to output the treated water to the leach field.

Other aspects and features of the present invention will become apparentto those ordinarily skilled in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way ofexample only, with reference to the attached Figures, wherein:

FIG. 1 shows an apparatus of the present invention connected to a house;

FIG. 2 shows a top view of an exemplary apparatus of the presentinvention;

FIG. 3 shows a side view of the apparatus of FIG. 2;

FIG. 4 shows a back perspective view of an apparatus of the presentinvention;

FIG. 5 shows a close up view of the perspective view of FIG. 4;

FIG. 6 shows a side perspective view of the apparatus of FIG. 4;

FIG. 7 shows a generic airlift pump system that can be used with theapparatus of FIG. 4;

FIG. 8 shows a front perspective view of the apparatus of FIG. 4;

FIGS. 9A and 9B show an embodiment of a turbine that can be used withthe apparatus of FIG. 4;

FIG. 10 shows a front functional view of the turbine of FIGS. 9A and 9B;

FIG. 11 shows a side view of the apparatus of FIG. 4;

FIG. 12A-12C show and embodiment of a rotatable shaft that can be usedwith the apparatus of FIG. 4;

FIG. 13 show how an apparatus of the present invention can be integratedwith a house;

FIG. 14 shows how the solid organic wastes extracted by a method ofpresent invention can be obtained; and

FIG. 15 shows an exemplary method of treating sewage of the presentinvention.

DETAILED DESCRIPTION

Generally, the present invention provides a system and method fortreating sewage and used water where they are generated, rather than ata centralized treatment plant. The system, or apparatus, receives sewageat a receiving compartment and separates solids from liquids at thereceiving compartment. The solids are extracted from the receivingcompartment by an auger. The liquid sewage flows through a series oftreatment compartment containing rotating biological contactor discs(RBCDs) for treatment by these RBCDs. The RBCDs are secured to arotating shaft. The rotating shaft and the auger are powered by aquasi-submerged turbine displaced by a flow of air.

FIG. 1 shows a top view of a block representation of a house 100 havingits sewage system (not shown) connected, through an inlet 104, to anexemplary embodiment of the sewage treatment apparatus 102 of thepresent invention. And outlet 106 propagates treated water from theapparatus 102 to a leach field 108, which can also be referred to as apolishing field. In the case of the apparatus 102 treating sewage forthree bedroom house, the size of the leach field 108 is typically 10 m²for permeable soils. Although a house 100 is shown at FIG. 1, the sewagetreatment apparatus of the present invention can be connected to a groupof houses, apartment buildings, cottages, restaurants, stores, or anyother suitable type of dwelling that produces sewage and used water. Thesewage treatment apparatus 102 will generally be located undergroundwith the inlet 104 also located underground; however, it can also becompletely or partially located above ground without departing from thescope of the present invention. As an alternative to be being locatedoutside the house, the apparatus can also be located, for example, in agarage or basement of the house 100.

FIG. 2 shows an open, top view of the exemplary apparatus 102. FIG. 3 isa side-elevational view taken along the line III-III of FIG. 2. Withrespect to FIGS. 2 and 3, the apparatus 102 comprises a housing 103 anda sewage receiver compartment (SRC) 110 formed within the housing 103.The SRC 110 receives sewage from the inlet 104 (sewage inlet). The inlet104, can be a pipe or any other suitable type of conduit such as, forexample, a tube. The sewage spilling into the SRC 110 typically containsmatters dissolved in water, as well as undissolved solid waste products.Some of the solid waste products settle, eventually, to the bottomportion 112 of the SRC 110.

FIG. 3 indicates a sewage level 114, above the V-shaped bottom 116 ofthe SRC 110. Also shown at FIG. 3 is an inclined auger 118 (which canalso be referred to as an Archimedes screw) rotatably secured at itsfirst end 120 to the V-shaped bottom 116. As will be described below, asecond end 122 of the auger is operationally connected to a turbine 124,shown at FIG. 2. As such, the turbine 124 rotates the auger 118, whichdisplaces the solid matter deposit from the bottom portion 112 to areceptacle 126. At regular intervals, or when required, the receptacle126 can be removed from the apparatus 102, for example through a hatch(not shown) and emptied to a composting field. This can provide compost,which can be use for horticulture purposes or for any other suitablepurposes.

As will be understood by the skilled worker, the bottom of the SRC 110need not be V-shaped. Rather, the bottom of the SRC 110 can have anysuitable convex shape where solid waste products can settle. Further,the first end 120 of the auger 118 need not be secured to the V-shapedbottom 116. Rather, the auger 118 can be mounted within the housing 103though any suitable means, such as, for example, brackets that positionthe first end 120 at the bottom portion 112 of the SRC 110.

As will be appreciated by the skilled worker, the benefit of separatingsolid waste from the sewage to obtain liquid sewage at the outset ofsewage treatment is that it diminishes the quantity of materials thatcan dissolve in the sewage, thereby simplifying the treatment of theliquid sewage.

The apparatus 102 also comprises treatment compartments in which sewageis treated. FIG. 2 shows a first treatment compartment 128, which is influid communication with the SRC 110 through an opening 130. The sewagepresent in the SRC 110 spills from the SRC 110 into the firstcompartment upon the sewage level 114, shown at FIG. 3, reaching theheight of the opening 130. FIG. 4, which is an open, back perspectiveview of the apparatus 102 also shows the water level 114 and the opening130. Although the representation of apparatus 102 as shown at FIGS. 2and 3 differs from that shown at FIG. 4, they are functionallyequivalent.

As will be understood by the skilled worker, the apparatus of thepresent invention can have any number of treatment compartments. Forexample, with reference to FIG. 2, the apparatus 102 comprises a secondtreatment compartment 132, which in fluid communication with the firsttreatment compartment 128 through one or more openings in the first wall134. The apparatus 102 further comprises a third treatment compartment136, which is in fluid communication with the second treatmentcompartment 130 through one or more opening in the second wall 138.

The apparatus 102 comprises a rotatable shaft 140 mounted in the housing103. As seen at FIG. 4, the rotatable shaft 140 has one end secured atthe bottom of a V-shaped groove 141 defined in a wall 139. The rotatableshaft 140 has secured thereto a series of disks 142 made of a biologicalcontactor material (RBCDs). Five, four, and three disks 142 are shown inthe first, second, and third treatment compartments (128, 132, and 136)respectively. Practically, the number of discs can depend on thebiological load to be treated by the apparatus 102. The disks can bemade of plastic, such as, for example, polythene, polyvinyl chloride,polystyrene, expanded polystyrene or of any other suitable material.Although not shown at FIG. 2, but as will be described below, therotatable shaft 140 is operationally connected to the turbine 124, whichrotates the rotatable shaft 140. As will be understood by the skilledworker the shaft can be made of any suitable rigid material such asplastic, high-density polyethylene (HDPE) etc. Further, the rotatableshaft 140 and discs 142 can be hollow and buoyant.

The apparatus of the present invention can also comprise a used waterreceiver compartment (UWRC) 146 as shown for the apparatus 102 at FIGS.2 and 4. The UWRC 146 is connected to a used water circuit (not shown)through a used water inlet 148. The used water circuit can include, forexample, used water from the household's bath and shower, and clotheswasher. The used water circuit is distinct from the sewage system thatspills its content in the SRC 110. By having the UWRC 146 separate fromthe SRC 110, increased dissolution of the solid waste products presentin the sewage is avoided upon used water being spilled into theapparatus 102 at the UWRC 146.

As seen at FIG. 4, the UWRC 146 is in fluid communication with the SRC110 through an overflow opening 150 through which sewage can spill fromthe SRC 110 into the UWRC 146 upon excessive sewage filling the SRC 110.The overflow opening 150 can have a filter 152 to prevent solids fromspilling into the UWRC 146. The filter 152 can be a comb filter or anyother suitable type of filter such as, for example, a mesh filter.

Also shown at FIG. 4 are a series of openings 154 defined by the wall139. The openings 154 allow fluid communication between the UWRC 146 andthe first treatment compartment 128. The openings 154 can be of anyshape and there can be any number of them. A used water level 156 isalso shown at FIG. 4. As will be understood by the skilled worker theused water level 156 is the same as the water level in the first, secondand third treatment compartments 128, 132, and 136, since these are allin fluid communication with each other. Further, as shown at FIG. 4, thediscs 142 are only partially submerged in the water, so as to enable thediscs to pass successively through the sewage and through the air,thereby causing micro-organisms to form on the biological contactormaterial and to consume a portion of the waste products present in thesewage, to produce treated water.

FIG. 5 shows a close up view of a region of the SRC 110 where theoverflow opening 150, the filter 152 and the sewage level 114 are shown.Also shown is a water diffuser 158 that receives treated water from anairlift pump system that will be described below. The treated waterprovided by the airlift pump to the water diffuser 158 pours out ofholes 160 and onto a filter assembly 162 that prevents solids fromspilling from the SRC 100 into the first treatment compartment 128.Although holes 160 are shown at the top portion of the water diffuser158, holes can be present at the bottom as well, or anywhere on thewater diffuser 158. The pouring of water from the diffuser 158 onto thefilter assembly 162 serves to clean out the filter assembly 162 ofsolids present in the filter assembly 162. Further, as will be discussedin more detail below, the airlift pump system re-cycles water from oneof the treatment compartments of the apparatus 110 back into the SRC110. This enables further treatment of the water. The diffuser 158 hasan opening 164 that can be accessed by a worker to clean out thediffuser 158 and the airlift pump system with a fish line or with anyother suitable flexible cleaning implement.

The filter assembly 162 is shown connected to the water diffuser 158through brackets 166; however, as will be understood by the skilledworker, the filter assembly can be mounted in the housing 103 in anyother suitable manner such as, through brackets connected to any of thewalls and partitions of the housing. The filter assembly 162 is shown asincluding a rounded member 163 on which water from the water diffuser158 falls. Secured to the rounded member is a fiber filter 161 (in acomb arrangement). Water falling on the rounded member 163 flows on therounded member 163, spreading itself as it flows down toward the fiberfilter. This allows for more thorough cleaning of the fiber filter 161.The fiber filter 161 can include a plurality of fibers 1 mm in diameter,forming a comb filter having a thickness of 6 mm, and spread out over awidth covering at least the width of the opening 130. The rounded membercan simply be a cut-out section of a conduit. As will be understood bythe skilled worker, any other type of filter assembly, coupled or not toa water diffuser can be used without departing from the scope of thepresent disclosure. As will be further understood by the skilled worker,the apparatus can function even without any filter assembly present.

FIGS. 4 and 5 also show a water outlet 175, which is, as will bedescribed below, also connected to an airlift system. Further, a vent173 is shown at FIGS. 4 and 5. The vent 173 enables ventilation of theapparatus 102.

As is shown at FIGS. 4 and 5, the SRC 110 of the exemplary apparatus 102comprises two sections 168 and 170, connected through and opening 172defined in the partition 174. The sewage inlet 104 spills sewage intosection 170. The sewage distributes itself between sections 168 and 170.Any solid waste matter in the sewage present in the section 168 caneventually settle to the slanted bottom of section 168 and, therefrom,slide down towards section 170 where it can settle to the bottom portion112.

As shown at FIG. 2, the apparatus 102 comprises a sedimentationcompartment 144, which is in fluid communication with the thirdtreatment compartment 136. The sedimentation compartment 144 is free ofdiscs 142 and allows for sediments in the sewage/treated water stillpresent in the sedimentation compartment to settle at the bottomthereof. The sedimentation compartment 144 is in fluid communicationwith a reservoir 145 through a conduit 123. A pump assembly (not shown)can be connected to the reservoir 145 to enable a user to use thetreated water present in the reservoir 145 for any suitable purpose suchas, for example, watering a lawn or horticulture arrangements.

FIG. 6 shows an open, side perspective view of the apparatus 102. Asseen at FIG. 6, the third treatment compartment 136 contains filtrationmedia 180 comprising buoyant pieces of material. The material can be thesame as that of which the discs 142 are made (for example HDPE, whichhas a density lighter than that of water). Although not shown at FIG. 6,the third treatment compartment is equipped with an air diffuserpositioned below the filtration media 180. The air diffuser supplies aflow of oxygen, present in the air, to the third treatment compartment136. Agitation of the filtration media is effected mainly given by therotation of disks in the third treatment compartment 136. The waterpresent in the third treatment compartment 136 being in an advance stageof treatment, combined with: the presence of the filtration media 180,the presence of oxygen and the agitation of the filtration media, allowsnitrification to occur continuously in the third treatment compartment136.

The agitation of the filtration media 180 ensures that matteraccumulated on the filtration media parts detaches to allow thetreatment process to continue (regenerate). In prior art treatmentsystems using filtration media, the supply of oxygen to the filtrationmedia has to be sufficiently high to allow agitation of the filtrationmedia. In the apparatus of the present invention, the presence of therotating discs 142 in the third treatment compartment also causesagitation of the filtration media 180, which reduces the required supplyof oxygen compared to prior art systems using filtration media. Althoughnot shown in the figures, small fins can be added to the discs 142 ofthe third treatment compartment to provide additional water agitation.The agitation of the filtration media 180 pieces allows micro-organismsand matter (biomass) accumulated on the pieces in question, to detachtherefrom and settle at the bottom of the apparatus 102.

As will be understood by the skilled worker, once nitrification of thetreated water present in the third treatment compartment 136 hasoccurred, denitrification of the treated water of third treatmentcompartment 136, or of any compartment downstream from the thirdtreatment compartment 136 (e.g., the sedimentation compartment 144) canbe effected by transferring (e.g., by using an airlift pump system) thetreated water in question to the SRC 110, for subsequent treatment inthe first treatment compartment 128. As will be further understood bythe skilled worker, it is the presence of particular organic matter inthe first treatment compartment that can allow denitrification to occur.

As mentioned previously in relation to FIG. 5, airlift pump systems canbe used in the apparatus 102. In the apparatus 102, the airlift pumpsystems are used to propagate treated water from any one of thetreatment compartment and/or sedimentation compartment to the SRC 110.FIG. 7 shows a generic example of an airlift pump system that can beused in the apparatus 102.

The airlift pump system of FIG. 7 includes a conduit 200 that can beplaced in any of the treatment compartments 128, 132, and 136, and/or inthe sedimentation compartment 144. A bottom section 202 of the conduit200 is placed adjacent a bottom portion of the apparatus 102. An airpump 204 is connected to the bottom section 202 through a tube 206. Theair pump 204 pumps air to the bottom section 202 to cause bubbles toform in the sewage/treated water present in the bottom section 202.These bubbles reduce the density of the sewage/treated water present inthe conduit 200, which causes the level of the sewage/treated water inquestion to rise above the used water level 156 (sewage/treated waterlevel) shown at FIG. 4. A conduit 208 is connected to the conduit 200.The conduit 208 is slanted towards the SRC 110 and has an output end210. Upon the level of sewage/used water rising up to connection level212 of the conduit 208 to the conduit 200, the sewage/used water in theconduit 200 enters the conduit 208 and propagates towards the output end210. The conduit 200 has another end 230 that can be connected to anaccess conduit to allow cleaning of the conduit 200. Alternatively, theend 230 can be capped or left open.

As will understood by the skilled worker comparing FIG. 5 to FIG. 7, thewater outlet 175 shown at FIG. 5 corresponds to the output end 210 ofthe conduit 208. Further, FIG. 4 shows a bottom section 216 of a conduitdisposed in the second treatment compartment 132, the bottom section 216being adjacent a bottom 218 of the apparatus 102. The bottom 218 can betrough-shaped as shown at FIG. 4, to allow sediments to accumulate atthe bottom of the trough. As will be understood by the skilled worker,in the case of FIG. 4, the bottom section 216 corresponds to the bottomsection 202 of the conduit 200 shown at FIG. 7. As previously mentionedthe water diffuser 158 and the water outlet 175 are each connected to anairlift pump system. They can be connected to a same airlift pump systemor to distinct airlift pump systems. In the latter case, a single pumpcan be used for both airlift pump systems or each airlift pump systemcan have its own pump. The air pump or air pumps, which can be diaphragmpumps or any other suitable type of air pump, can be located inside thehousing 103 of the apparatus or outside the housing without departingfrom the scope of the present disclosure. By using airlifts pumpsystems, sediments settling at the bottom of the treatment compartmentsand/or sedimentation compartment can be periodically pumped to SRC 110.This overcomes the need to have sludge pumping trucks service theapparatus 102.

FIG. 6 shows a first access conduit 250 connected to an airlift pumpsystem (not shown) pumping water from the sedimentation compartment 144to the water diffuser 158 of FIG. 5. FIG. 6 further shows a secondaccess conduit 252 connected to another airlift pump system (not shown)pumping water from the second treatment compartment to the water outlet175 of FIG. 5. Flexible cleaning implements can be introduced in theaccess conduits 250 and 252 to clean the conduits of their respectiveairlift pump systems. FIG. 6 also shows the turbine 124 disposed in aturbine compartment 254, between walls 256 and 258.

FIG. 8 shows an open, cut-through, perspective view of the apparatus102. The wall 256 is not shown to allow a better view of the turbine 124and of its connection to the auger 118 and to the rotatable shaft 140.The turbine 124 is shown as being open in order to view the turbinechambers 300; however, these chambers are covered by a disc-shaped wall,as will be described further below. The turbine is mounted to the walls256 (not shown) and 258 at a level where it is quasi-completelysubmerged. An air conduit 265, connected to an air source (e.g., apump), expresses air which powers the turbine 124.

The turbine 124 is connected to a sprocket assembly 260 secured to thewalls 256 (shown at FIG. 6) and 258. A first chain 262 connects theturbine 124 to the sprocket assembly 260. The first chain 262 engages asprocket (not shown) mounted on a hub 264 of the turbine 124 and asprocket 266 of the sprocket assembly 260. The sprocket assembly 260 isconnected to the auger 118 through a second chain 268 that engages asprocket (not shown) of the gear assembly 260 and a sprocket 270 of theauger 118. Although not shown, the second end 122 of the auger 118 isrotatably mounted in the housing 103. The sprocket assembly 260 is alsoconnected to the rotatable shaft 140 through a third chain 272 securedto a sprocket 274 of the sprocket assembly 260, and to a sprocket 276mounted on the rotatable shaft 140.

As the turbine 124 rotates, the sprocket and chain system will turn theauger 118 to displace solid matter deposits from the bottom portion 112of the SRC 110 to the receptacle 126. Further, as the turbine 124rotates, the sprocket and chain system will turn the rotatable shaft 140to cause the discs 142 to successively pass through sewage and air,thereby causing micro-organisms to form on the discs 142 and to consumewaste products present in the sewage.

As will be understood by the skilled worker, the size ratio of thesprockets interconnecting the turbine 124 to the auger 118 and to therotatable shaft 140 determines the rotation speed of the auger 118 andof the rotatable shaft with respect to that of the turbine 124.Typically, the turbine 124 can rotate at 0.3 rotation per minute (rpm),the auger 118 at 0.1 rpm, and the rotatable shaft 140 at 1.3 rpm. Aswill be understood by the skilled worker, any other suitable rotationspeeds can be used depending on various factors, including, for example,the biological load to be treated by the apparatus 102 and the surfacearea of the discs 142.

As will be understood by the skilled worker, the turbine 124 can beoperationally coupled to the auger 118 and the rotatable shaft 140through any other suitable means such as, by belts and pulleys insteadof chains and sprockets.

Although not shown at FIG. 8, the turbine compartment can be in fluidcommunication with the sedimentation compartment 144 though openingsdefined in the wall 256 below the water level 176. In such a case, theopenings in question can be at the bottom region of the wall 258.Additionally, the bottom of the turbine compartment 254 can be builtinclined towards the sedimentation compartment 144 to allow anysediments accumulated in the turbine compartment 254 to slide out of theturbine compartment 254, into the sedimentation compartment 144, wherean airlift pump system can be used to transfer these sediments to theSRC 110. Alternatively, the turbine compartment 254 can contain a bodyof water that does not communicate with that of the sedimentationcompartment 144. Further, as shown at FIG. 8, a fan 278 can bepositioned in an opening in the wall 258 to provide added ventilation tothe apparatus 102.

The rotatable shaft can be held in place at the first one 139 and at thewall 139 (FIG. 4), and at the wall 258, through a bushing assembly (notshown). The rotatable shaft can also be held in place at any walldelimiting the treatment/sedimentation compartments through similarmeans. As will be described below, the rotatable shaft 140 can be abuoyant (floating) rotatable shaft. Such a floating rotatable shaft isdescribed below. By using a buoyant (floating) shaft of a properlychosen diameter, the use of intermediate support points, andcorresponding bushings, at the various treatment compartments can beeliminated. By using a floating shaft most of the friction can besubstantially limited to a contact area between the shaft/disk and thewater. Vertical loads on the shafts/disks are directly transferred tothe water. A floating shaft avoids the need of bearings and bushings,which can greatly simplify long-term maintenance of the apparatus 102.To increase the buoyancy of the shaft/discs, the discs can be hollowedout.

FIGS. 9A and 9B respectively show a perspective view and an open, sideview of the turbine 124. The turbine 124 has a pair of spaced-apart,disc-shaped walls 298. First partitions 302 are formed between thedisc-shaped walls 298 and each of the first partitions 302 extendsradially outwards from the hub 264, towards a perimeter 304 of thedisc-shaped walls 298. The angle between adjacent first partitions 302can be substantially the same for all pairs of adjacent firstpartitions. The disc-shaped wall 298 and the first partitions 302 definethe chambers 300 of the turbine 124.

The turbine 124 has second partitions 306 connected to the disc-shapedwalls 298 and to respective first partitions 302. Each of the secondpartitions 309 and first partitions 302 are at an angle of 90°. However,the angle can be either larger or smaller than 90°. In any case, theangle should be less than 180°.

The turbine 124 further has third partitions 308 that are connected tothe disc-shaped walls 298 and to respective second partitions 306. Eachof the third partitions 308 and first partitions 302 are at an angle toeach other that is less than 90°. Additionally, each of the thirdpartitions 308 extends from its respective second partition 306 over anadjacent second partition 306. This defines a passageway 310 connectingan outside of the turbine 124 to a respective chamber 300. Even thoughthe angle between the third partitions and the first partition is shownat FIG. 9B as being less than 90°, angles of 90° or above could alsowork.

FIG. 10 shows an open, side view of the turbine 124 in operation. Theturbine 124 is quasi-submerged in the water present in the turbinecompartment 254. However, the turbine 124 can be totally submerged orpartially submerged without departing from the scope of the disclosure.An air source (shown at reference numeral 265 at FIG. 8), located belowthe turbine 124 produces air that enters the chambers 300 through thepassageways 310. This causes water to be expressed out off the chambers300 that are receiving air. The entry of air in chambers 300 causes theturbine 124 to develop a torque and the turbine 124 to turn in thedirection indicated by arrow 312.

As will be understood by the skilled worker, the extension of the thirdpartitions 308 over adjacent second partitions 306 ensures that thecompartments 300 retain air therein until the respective passageways 310turns upwards to allow water to enter the chambers. The longer air staysin the chambers 300, the greater the torque developed by the turbine 124will be.

The relatively small dimension of the passageways 310 with respect tothe chambers 300 causes rapid and prolonged flow of water through thepassageways 310 as water enters the turbine 124 to fill the chambers300. This rapid and prolonged flow of water prevents excessive build upof sediments in the passageways 310 and in the chambers 300. FIG. 11shows another open, side perspective view of the exemplary apparatus102. An air conduit 400 can be connected at one end to the fan 278 shownat FIG. 8. The other end of the conduit 400 is connected to an openingin a removable partition 410 that overhangs the receptacle 126, whichcan be a standard recycling or composting receptacle. FIG. 11 also showsaccess panels 401 behind which can be stored an electrical pumpingsystem to pump out treated water from the reservoir 145.

FIGS. 12A-12C show a buoyant rotatable shaft (BRS) 500 to which aresecured discs 142. The BRS 500 can be used instead of the rotatableshaft 140 without departing from the scope of the present disclosure.The BRS 500 and the discs 142 can be made of high density polyethylene(HDPE) or of any other suitable material. The BRS 500 includes plates502 and 504 that are used to slidably secure the BRS 500 within theapparatus 102, as a body 506 and a sprocket 508 for couple to the chain272 of FIG. 8. FIG. 12A shown the plates 502 and 504 separate from thebody 506; FIG. 12B shows the plates 502 and 504 secured to the body 506;and FIG. 12C shows a cross-sectional view of FIG. 12B taken along theline XIIC-XIIC. The inside 510 shown at FIG. 12C is hollow. Further, thediscs 142 can be hollow. Manufacturing such hollow discs can include,for example, starting out with two full 0.25 inch thick discs.Subsequently, in each disc, a recess of about 0.125 inch deep is formed(by machining or by any other suitable process). The two discs are thenbrought together and glued with their recesses facing each other. Thisproduces a hollow disc of 0.5 inch in thickness.

With respect to FIG. 4, in the case where the BRS 500 were used insteadof the rotatable shaft 140, the V-shaped groove 141 in the wall 139could be replaced by a vertical slot. The first plate 500 would belocated in the UWRC 146 and be connected to the body 506 of the BRS 500.This would enable a vertical sliding engagement of the BRS 500 withrespect to the wall 139. With respect to FIG. 8, the wall 258 would inthis case also include a slot and the plate 504 would be located in theturbine compartment 254 and be connected to the body 506 of the BRS 500.This would enable a vertical sliding engagement of the BRS 500 withrespect to the wall 258. As such, BRS 500 would effectively float in theused water and would be allow vertical movement to accommodatefluctuations in the used water level 176, or fluctuations in the weightof the BRS 500/discs 142 due to the accumulation of sediments on thediscs 142. The chain and sprocket assembly can be assembled such thatthere is adequate slack in the chain 272. Alternatively, any suitablechain-tensioning device can be used with the chain 272.

As will be understood by the skilled worker, the plates 502 and 504 canbe secured to the body 506 though any suitable means such as, forexample, by complementary treads on the plates and body, by fasteners,by snap fits, etc.

FIG. 13 shows an overview of the exemplary apparatus 102 connected tothe house 100. The house 100 can have a water supply 600, such assupplied by a well (not shown), and an outside water supply 602, forexample, a municipal water supply. The output of the bath/shower 604 andof the linen washer 606 can be connected to the UWRC 146 of theapparatus 102. The output of the toilet 608, the bathroom sink 610, thedishwasher 612, the kitchen sink 614, and the garburator 616 can all beconnected to the SRC 110 of the apparatus 102. The house 100 is shownwith a vent 618. A dedicated vent 620 can also be connected to theapparatus 102. The receptacle 126 is shown outside the apparatus 102 toindicate that its contents can be emptied to a composting field. Thereceptacle 126 will typically contain undissolved solids from the toilet608 and sinks 610 and 614, as well as crushed kitchen waste from thegarburator 616. Additionally, as will be understood by the skilledworker, the receptacle 126 can contain mineralized matter obtainedthrough an aerobic decomposition process of the solid waste received atthe apparatus 102, as well as matter obtained from an anaerobicdecomposition process of the solid waste received at the apparatus 102.As depicted by an arrow 622, the apparatus 102 outputs treated water toa polishing field.

FIG. 14 shows an exemplary method for recycling organic matter obtainedfrom the apparatus 102. At step 700, the receptacle 126 is taken out ofthe apparatus 102 and is exposed to sunlight at step 702. An emptyreceptacle is substituted to the one taken out of the apparatus. Theexposure of the receptacle 126 to sunlight during the summer months,allows for destruction of pathogens by dessication. At step 704, thecontents of the receptacle 126 is emptied and mixed, in any suitableproportion, with soil. This mixture, once determined safe, could be usedimmediately as a fertilizer for ornamental horticulture. After a periodof time, for example, one year, the soil/organic matter mixture could beused as a fertilizer harvesting crops. At step 706, the emptiedreceptacle 126 can be returned to the apparatus 102 upon the receptacleinstalled in the apparatus being removed to go be subjected to steps702, 704, and 706.

FIG. 15 shows an exemplary method of the present invention for treatingsewage. At step 900, sewage is received at a sewage receivingcompartment (SRC). At step 902, solids present in the sewage areseparated from the sewage. As a result, solids and liquid sewage areproduced. As will be understood by the skilled worker, the liquid sewagecan still contain solids therein; however these will be in much quantitythan that originally received at the SRC. At step 904, the solid aredisplaced from the SRC towards a receptacle, and at step 906, the solidsare extracted from the receptacle.

At step 908, the liquid sewage is provided to a first treatmentcompartment for treatment by RBCDs. At step 910, the liquid sewage isprovided to a second treatment compartment by RBCDs. At step 912, liquidsewage (also referred to simply as sewage or as treated water) from thesecond compartment is provided to the SRC. Step 912 can occur any numberof times during a day for any amount of time (e.g., four times a day,thirty minutes each time).

At step 914, the liquid sewage is provide to a third treatmentcompartment for treatment by RBCDs and, optionally, by a filtering media(which can also be referred to as a fluidized filter bed treatment). Atstep 916, the liquid sewage is provided to a sedimentation compartment.At step 918, liquid sewage from the sedimentation compartment isprovided to the SRC. Step 918 can occur any number of times during a dayfor any amount of time (e.g., four times a day, thirty minutes eachtime). Steps 912 and 918 can occur simultaneously be powered by a sameair pump.

Finally, at step 920, the liquid sewage, which at this point isrelatively clean treated water, is output to a leach field where anymatter still present in the liquid sewage can break down in the leachfield.

As will be understood by the skilled worker, the apparatus 102 can beequipped with an alarm system that can signal the break of a chain orthe failure of a pump. The alarm can be sent to a service provider forthe apparatus 102. Upon detecting the alarm, the service provider cancarry out the required maintenance. If a chain fails and/or therotatable shaft stops turning for any reason, the media in the thirdtreatment compartment will still treat the water. This is advantageousin that the user of the apparatus is not likely to be left withoutsewage treatment capability. As stated above, the discs 142 in the thirdtreatment compartment can be equipped with fins to increase wateragitation. Discs 142 in other treatment compartments can also beequipped with such fins.

In the exemplary apparatus 102 shown at, e.g., FIG. 6, the firsttreatment compartment 128 is connected to the second treatmentcompartment 132 through an opening (not shown) at the bottom region ofthe wall 134 (FIG. 2). As such, the sewage flows generally downwardlyfrom the opening 130 through which the sewage is received from the SRC110, through to the second treatment compartment. This downwardly flowcan favor accumulation of solid matter near the junction between thefirst treatment compartment and the second treatment compartment. Assuch, an airlift pump system installed at that junction will helpre-circulate that solid matter back to the SRC 110.

Further, in the apparatus 102, the second treatment compartment 132 isconnected to the third treatment compartment 136 though slots 800 (onlyone is shown in the example of FIG. 6) in the wall 138. This causes thesewage to flow generally upwardly from the opening at the bottom regionof the wall 134 towards the slots 800.

Furthermore, the apparatus 102, the third treatment compartment 136 isconnected to the sedimentation compartment 144 through and opening 802at the bottom of the wall 804. As such, the sewage flows generallydownwardly from the slots 800, through to the sedimentation compartment.This downwardly flow can favor accumulation of solid matter near thejunction between the third treatment compartment and the sedimentationcompartment. As such, an airlift pump system installed at that junctionwill help re-circulate that solid matter back to the SRC 110.

Although not depicted in the figures, the apparatus of the presentinvention can be provided with one or more access cover. The apparatusof the present disclosure can be of any suitable size and have anysuitable number of treatment compartment and any suitable number ofdiscs. The size, number of discs and/or of treatment compartments willtypically be determined by the occupancy of the house/building, or groupthereof, to which the apparatus is connected. For a three-bedroom house,the apparatus can have length of 7 feet (about 2.1 m), a width of 3.5feet (about 1.05 m), and a height of 5.6 feet (about 1.68 m). The sizeof the polishing field (leach field) for such an apparatus isapproximately 10 m². The diameter of the discs 142 (RBCDs) can be ofabout 2.6 feet (about 78 cm). The spacing between the discs can be ofabout ¾ inch (about 20 mm). The diameter of the turbine can be about 34inches (about 70 cm) by 6 inches thick (about 15 cm).

The housing of the apparatus of the present disclosure can be made ofany suitable materials such as concrete, aluminum, fiberglass, plastic(for example, polypropylene, polyethylene, polycarbonate, HDPE, etc.),and plastic/resin mixtures. The materials used in fabricating thevarious compartments, the rotatable shaft, the discs, the turbine etc.,in the apparatus can also be made of the above-noted plastics or of anyother suitable materials. The components of the apparatus can be securedto each other through any suitable means such as epoxies fasteners etc.Further, the apparatus of the present disclosure can be made in moldedsections to be assembled through any suitable process. The moldedsections can be made through injections molding or any other suitablemolding process.

As will be understood by the skilled worker, although shown with theUWRC 146, the reservoir 145, the filtration media 180, and airlift pumpsystems the apparatus of the present invention can function withoutthese. Further the apparatus of the present invention can function withany suitable flow of sewage (downwardly, upwardly or other) from onetreatment compartment to another without departing from the scope of thepresent disclosure.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments of the invention. However, it will be apparent to oneskilled in the art that these specific details are not required in orderto practice the invention.

As discussed above, the present invention provides a system and methodfor treating sewage, rather than at a centralized treatment plant. Thesystem, or apparatus, receives sewage at a receiving compartment andseparates solids for liquids at the receiving compartment. The solidscan be extracted from the receiving compartment by an auger. The liquidsewage flows through a series of treatment compartment containing RBCDsfor treatment by these RBCDs. The RBCDs are secured to a rotating shaft.The rotating shaft and the auger are powered by a quasi-submergedturbine displaced by a flow of air. Advantageously, the apparatus of thepresent disclosure does not require periodic pumping of sludge by aservice truck. Rather, any sediments formed at the bottom of theapparatus is pumped back, a few times a day, into the sewage receivercompartment where sediments can settle and be removed by the auger.

The above-described embodiments of the invention are intended to beexamples only. Alterations, modifications and variations can be effectedto the particular embodiments by those of skill in the art withoutdeparting from the scope of the invention, which is defined solely bythe claims appended hereto.

1. An apparatus for treating sewage, the sewage including water andwaste products, the apparatus comprising: a housing; a sewage receivercompartment formed within the housing, the sewage receiver compartmenthaving a sewage inlet to receive the sewage therefrom, the sewagereceiver compartment having a bottom portion, some of the waste productsin the sewage to sink to the bottom portion to form a solid matterdeposit; a first treatment compartment formed within the housing, thefirst treatment compartment being in fluid communication with the sewagereceiver compartment, the first treatment compartment to receive thesewage from the sewage receiver compartment; an auger mounted within thehousing, the auger having first and second ends, the first end beingdisposed at the bottom portion of the sewage receiver compartment; areceptacle disposed outside the sewage receiver compartment, adjacentthe second end of the auger; a rotatable shaft mounted in the housing,the rotatable shaft extending through the first treatment compartment,the rotatable shaft having a biological contactor material securedthereto, the biological contactor material being disposed in the firsttreatment compartment; a turbine compartment formed within the housingin fluid communication with the first treatment compartment; a turbinerotatably mounted in the turbine compartment and operationally connectedto the rotatable shaft and to the second end of the auger; an air sourceoperationally coupled to the turbine, the air source to turn theturbine, the turbine to rotate the rotatable shaft, the biologicalcontactor material successively passing though the sewage, and throughair, as the rotatable shaft rotates, the successive passage of thebiological contactor material through the sewage and through the aircausing micro-organisms to form on the biological contactor material andto consume a portion of the waste products present in the sewage, toproduce treated water, the turbine also to rotate the auger, the augerto displace, upon rotation, the solid matter deposit from the bottomportion of the sewage receiver compartment to the receptacle; and anoutlet in fluid communication with the first treatment compartment, andwith a leach field, to output the treated water to the leach field. 2.The apparatus of claim 1, further comprising a filter formed between thesewage receiver compartment and the first treatment compartment, thefilter to prevent waste products that have a size greater than apre-determined size, to flow into the first treatment compartment. 3.The apparatus of claim 1, further comprising a used water receivercompartment to receive, independently from the sewage receivercompartment, used water, the used water receiver compartment being influid communication with the first treatment compartment.
 4. Theapparatus of claim 3 wherein the sewage receiver compartment includes anoverflow outlet in fluid communication with the used water receivercompartment, to allow sewage to spill from the sewage receivercompartment into the used water receiver compartment, upon a sewagelevel in the sewage receiver compartment exceeding a predeterminedlevel.
 5. The apparatus of claim 4 wherein the overflow outlet includesa filter to prevent waste products that have a size greater than apre-determined size, to flow into the used water receiver compartment.6. The apparatus of claim 2 wherein the biological contactor materialincludes a first plurality of biological contactor discs.
 7. Theapparatus of claim 6 wherein the discs are made of a plastic.
 8. Theapparatus of claim 7 wherein the plastic includes at least one ofpolythene, polyvinyl chloride, polystyrene, expanded polystyrene,polycarbonate, and polypropylene.
 9. The apparatus of claim 1 whereinthe first air source is operationally coupled to the turbine though anair conduit having an output end disposed adjacent a bottom of theturbine compartment, the output end to direct air towards the turbine.10. The apparatus of claim 9 wherein the turbine includes: a hub; a pairof spaced-apart, disc-shaped walls; first partitions formed between thedisc-shaped walls, each partition extending substantially radially fromthe hub towards a perimeter of the disc-shaped walls, the firstpartitions being substantially equi-angularly-spaced from each other,the disc-shaped walls and adjacent pairs of first partitions defining aplurality of chambers in the turbine; second partitions connected to thedisc-shaped walls and to respective first partitions, each of the secondpartitions being connected to a respective first partition at a firstangle, the first angle being less than 180°; and third partitionsconnected to the disc-shaped walls and to respective second partitions,each of the third partitions and its respective first partitions beingat a second angle to each other, the second angle being less than 90°,each third partition extending from its respective second partition overan adjacent second partition, to define a passageway connecting anoutside of the turbine to a respective chamber, the output end of theair conduit directing air substantially towards an opening of apassageway.
 11. The apparatus of claim 6 further comprising a secondtreatment compartment in fluid communication with the first treatmentcompartment and with the outlet, the second treatment compartment beinglocated between the first treatment compartment and the outlet, therotatable shaft extending through the second treatment compartment, therotatable shaft having a second plurality of biological contactor discssecured thereto, the second plurality of biological contactor discsbeing disposed in the second treatment compartment, the second pluralityof biological contactor discs to further treat the used water, thetreated water flowing from the first treatment compartment, through thesecond treatment compartment towards the outlet.
 12. The apparatus ofclaim 11 further comprising a third treatment compartment in fluidcommunication with the second treatment compartment and with the outlet,the third treatment compartment being located between the secondtreatment compartment and the outlet, the rotatable shaft extendingthrough the third treatment compartment, the rotatable shaft having athird plurality of biological contactor discs secured thereto, the thirdplurality of biological contactor discs being disposed in the thirdtreatment compartment, the third plurality of biological contactor discsto further treat the used water, the treated water flowing from thefirst treatment compartment, through the second and third treatmentcompartments towards the outlet.
 13. The apparatus of claim 12 whereinat least one of the first, second, third treatment compartments includespositively buoyant filtration media and a second air source to activatethe positively buoyant filtration media.
 14. The apparatus of claim 13wherein the positively buoyant filtration media includes a plurality ofbuoyant pieces.
 15. The apparatus of claim 12 further comprising asedimentation compartment in fluid communication with the thirdtreatment compartment and with outlet, the sedimentation compartmentbeing located between the third treatment compartment and the outlet,the treated water flowing from the first treatment compartment, throughthe second and third treatment compartments, and through thesedimentation compartment, towards the outlet.
 16. The apparatus ofclaim 15 further comprising a first airlift pump in fluid communicationwith a bottom region of the sedimentation compartment, the first airliftpump to pump sediments and treated water from the bottom of thesedimentation compartment into the sewage receiver compartment.
 17. Theapparatus of claim 16 wherein the sediments and treated water pumped bythe first airlift pump are directed to flow onto the filter to clean thefilter.
 18. The apparatus of claim 16 further comprising a secondairlift pump in fluid communication with the second treatmentcompartment, the second airlift pump to pump sediments and treated waterfrom the bottom of the second treatment compartment, into the sewagereceiver compartment.
 19. The apparatus of claim 15 further comprising afirst wall separating the first and second treatment compartments, thefirst wall defining a first opening between the first and secondtreatment compartments, the first opening connecting a bottom region ofthe first treatment compartment to a bottom region of the secondtreatment compartment, used water spilled from the sewage receivercompartment into the first treatment compartment, flowing downwardlyinto the first treatment compartment towards the first opening andtowards the second treatment compartment.
 20. The apparatus of claim 19further comprising a second wall separating the second and thirdtreatment compartments, the second wall defining a second openingbetween the second and third treatment compartments, the second openingbeing at a height greater than a height of the first opening, used waterentering the second treatment compartment at the first opening, flowingupwardly in the second treatment compartment towards the second openingand towards the third treatment compartment.
 21. The apparatus of claim20 further comprising a third wall separating the third treatmentcompartment from the sedimentation compartment, the third wall defininga third opening between the third treatment compartment and thesedimentation compartment, the third opening being a height less thanthe height of the second opening, used water entering the thirdtreatment compartment at the second opening, flowing downwardly in thethird treatment compartment towards the third opening and towards thesedimentation compartment, the outlet having a port in the sedimentationcompartment, the port being at a port height greater than the height ofthe third opening, used water entering the sedimentation compartment atthe third opening, flowing upwardly towards the port.
 22. The apparatusof claim 18 wherein the first airlift pump and the second airlift pumpinclude access ports for cleaning.
 23. The apparatus of claim 1 furthercomprising a vent fluidly connecting an interior of the apparatus toatmosphere, and a ventilator to create an air flow inside the apparatus.24. The apparatus of claim 1 further comprising a chain and sprocketassembly to operationally connect the turbine to the auger and to therotatable shaft.
 25. The apparatus of claim 21 wherein the outletincludes a treated water reservoir formed between the port and the leachfield.
 26. The apparatus of claim 1 wherein the rotating shaft is abuoyant shaft.
 27. The apparatus of claim 1 wherein the apparatusincludes a trough-shaped bottom.